Globe for arc-lamps.



PATENTED JUNE 7, 1904.

S. E. DOANE. GLOBE FOR ARC LAMPS.

APPLIOATIQN FILED JUNE 24. 1903.

R0 MODEL.

. Lavenfow? Patented June '7, 1904.

PATENT OFFICE.

- UNITED STATES SAMUEL EVERETT DOANE, OF CLEVELAND, OHIO, ASSIGNOR TOTHE FOS- TORIA BULB AND BOTTLE COMPANY, OF FOSTORIA, OHIO, A CORPO-RATION OF OHIO.

GLOBE FOR ARC-LAMPS.

SPECIFICATION forming part of Letters Patent No. 762,029, dated June 7,1904.

Applicatisn filed June 24,1903.

To all whom it may concern:

Be it known that I, SAMUEL EVERETT DOANE, a citizen of the UnitedStates, residing at Cleveland, in the county of Ouyahoga and State ofOhio, have invented a certain new and useful Improvement in Globes forArc-Lamps, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings.

In inclosed-arc lamps it has been found essential to employ an innerglobe of comparatively small size surrounding the carbons and containingthe burned-out air. In order that there shall be no circulation of freshair through the globe, it is necessary that the ends of the globe fitthe cooperating portions of the lamp snugly; but as-the globe from itsproximity to the arc is subjected to considerable heat its longitudinalexpansion prevents it being clamped tightly. Therefore it has beencustomary in employment of inner globes with inclosed-arc lamps tosecure the globe at the lower end in a more or less yielding manner andat the upper end to allow it to abut against a suitable head. Such headis frequently made of metaland has up-and-doWn play and rests on theupper end of the globe. Now in the operation of the lamp and in theremoval and replacement of the globes for trimming the lamp the globesare frequently broken, and the aggregate expense of operating the lampis thus considerably increased. I have discovered that the breakage iscaused to a very large degree by the mechanical impingement of theextreme end of the globe with its cooperating head, both by the lampitself, due to the jerks when the arc flashes or sputters, and by theoperator removing or replacing the globe.

The purpose of the present invention is to provide a globe in which suchbreakage shall be prevented or reduced to a minimum.

The ends of the globes heretofore used are usually ground to make asubstantially tight joint with the cooperating head, and thus the blowcomes upon the weakest part of the globe, where the ski-n of the glasshas been removed by the grinding, and starts a crack,which trav- SerialNo. 162,841.

(No model.)

els along the globe. I provide for the globe a ring-shaped cap, whichcontacts with its outer surface some distance beyond the extreme end ofthe globe and then extends toward the end of the globe and across theend without contacting therewith. The cap makes a'substantially tightjoint with the usual head for the globe, and when this cap contacts withsuch head the blow is carried by the cap to the outer surface of theglobe, where it is delivered in a glancing manner and against a surfacefully protected by the skin of theglass. I fill in the space between thering-shaped cap and the extreme end of the globe with some suitablecement, preferably an elastic cement, which securely fastens the ring tothe globe. I have found by thorough test that such a cap fully protectsthe end of the globe and practi cally does away with the breakage. Thecap makes a connection with the head as good as or better than theground-glass edge.

The drawings clearly illustrate my invention.

Figure l is a side elevation of the lower portion of an inclosed-arclamp having my globe with the cap applied to the upper end thereof. Fig.2 is a vertical section through the upper portion of the globe and thecooperating head.

Referring to the parts by letters, A represents the frame of the lamp, Bthe upper carbon, and O the lower carbon. The lower carbon is suitablyheld by the lower-carbon holder D, which may also hold the lower end ofthe globe in any suitable manner. These details may be of any formdesired.

The globe itself is designated E. At its upper end it is designed tomake close contact with the head F, which surrounds the upper carbon andis loosely guided by the hook a. of the frame member a and rests bygravity on the upper end of the globe. The ring cap,

which I have shown on the upper end of the globe, is designated Grand ispreferably made of brass and lies on the outside of the globe. Its uppersurface g is preferably flat to make a snug contact with the head F.From the outer edge of this surface 9 the ring extends downward, as at9, preferably in a flaring manner, but not flaring so much as the globe,so that the cap contacts first with the globe some distance below theextreme end thereof. Thus from the lower edge of the metal ring all theway up it is out of contact with the globe. The flat portion 1 of thering is some distance above the extreme edge of the globe, and this flatportion extends inward somewhat farther than the inner surface of theglobe.

It is customary to provide the head F with a downward bell-likeprojection f, from which leads the airpassage f, and to protect theglobe when being removed or replaced from contacting with thisprojection I form ashort downward flange on the inner edge of theprotecting-ring. Between the ring and globe I place suitable cement H,preferably one of the well known elastic cements, to permanently securethe cap to the globe and make an air-tight connection between them.

Having described my invention, I claim 1. A glass globe open at its endand protected by a ring which is permanently cemented to it out ofcontact with the extreme end of the globe, but contacts with the sidesurface of the globe and extends beyond the end thereof, substantiallyas described.

2. A glass globe open at its end and protected by a ring-shaped capwhich is permanently secured to it out of contact with the extreme endof the globe, but contacts with the side surface of the globe andextends across the extreme end thereof, substantially as described.

3. A glass globe open at its end and protected by a ring-shaped capwhich is out of contact with the extreme end of the globe but contactswith the outer side of the globe and extends across the extreme end,substantially as described.

4. The combination, with an inclosed-arc lamp, of an inner globetherefor, a protectingcap permanently carried by said globe, a member ofthe lamp with which said cap is adapted to contact, said cap being outof contact with the extremeend of the globe but contacting with theouter surface thereof, and filling making an air-tight connectionbetween the cap and the globe, substantially as described.

5. The combination, with a glass globe open at its end, of aprotecting-cap contacting with the outer surface of the globe somedistance from the extreme end, said cap continuing out of contact withthe globe beyond the end and then having a portion extending inwardlyacross the end of the globe but out of contact therewith, substantiallyas described.

6. The combination, with a glass globe open at its end, of aprotecting-cap contacting with the outer surface of the globe somedistance from the extreme end, said cap continuing out of contact withthe globe beyond the end and then having a portion extending inwardlyacross the end of the globe but out of contact therewith, and thenhaving an inwardly-extending flange out of contact with the globe, andcement between the cap and the globe, substantially as described.

7. A glass globe for an arc-lamp having an open end and a ring-shapedcap for protecting said end, said cap being secured to the globe out ofcontact with the extreme end thereof and passing across said extreme endand having at its innermost periphery a flange extending toward theinterior of the globe, substantially as described.

In testimony whereof I hereunto affix my signature in the presence oftwo, witnesses.

SAMUEL EVERETT DOANE.

Witnesses:

ALBERT H. BATES, N. L. BRESNAU.

